The kinematic differences between off-spin and leg-spin bowling in cricket

Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling.     

对现代化图书馆建设发展的认识与探索

本文从八个方面阐述了对现代化图书馆建设与发展的认识 ,并在图书馆管理方面进行了有益的探索 ,提出了一些新的管理理念     

工科研究生随机过程教学内容的思考

对工科硕士研究生随机过程课程教学内容的更新提出了自己的看法,阐述了随机过程课程在研究生教育中的作用及其重要性,并对课程内容更新的必要性和可行性进行了探讨。     

打造传媒巨舰搏击市场风浪--记湖南省广播电视局党组书记、局长、湖南广播影视集团董事长魏文彬

魏文彬率先提出媒体产业化道路、电视台机制改革、资本运营和文化产业市场化。魏文彬成了“电视湘军”的领头人。他自写的一副对联“变比拼为联合，走出湖南，寻找新对手；由分散到集中，面向世界，冲刺新目标”，是在新世纪进一步打造湖南传媒巨舰的新思路。     

网络经济时代传统企业管理理念的变革

随着计算机技术的发展，特别是Internet技术的应用和普及，人类已步入网络经济时代。作为网络经济时代主流的商业模式——电子商务，对传统企业的经营管理造成巨大的冲击和影响。传统企业的管理理念发生了巨大的变革：从“传统商务”向“电子商务”的转变。     

用直接代数法研究一些特殊非线性系统的行波激发模式

运用直接代数法研究一些特殊非线性系统:sine-Gordon系统和Bullough-Mikhailov系统的行波激发模式,得到了上述系统的孤波解、周期波解和双周期波解。     

Random vibration analysis of switching apparatus based on Monte Carlo method

The performance in vibration environment of switching apparatus containing mechanical contact is an important element when judging the apparatus’s reliability. A piecewise linear two-degrees-of-freedom mathematical model considering contact loss was built in this work, and the vibration performance of the model under random external Gaussian white noise excitation was investigated by using Monte Carlo simulation in Matlab/Simulink. Simulation showed that the spectral content and statistical characters of the contact force coincided strongly with reality. The random vibration character of the contact system was solved using time (numerical) domain simulation in this paper. Conclusions reached here are of great importance for reliability design of switching apparatus.     

《电场》单元检测题

一、选择题1.下面关于电场的叙述正确的是()A.两个未接触的电荷发生了相互作用,一定是电场引起的B.只有电荷发生相互作用时才产生电场C.只要有电荷存在,其周围就存在电场D.A电荷受到B电荷的作用,是B电荷的电场对A电荷的作用2.两个半径相同的金属小球,带电量之比为1∶7,相距为r,两者相互接触后再放回原来的位置上,则相互作用力可能为原来的()3A..如74图1所B.示37,在xC.97D.176轴上关于原点对称放置两个带相同电量的点电荷q1和q2,则对y轴上一点P的场强的方向能作出的判断是()A.可能沿y轴正向B.可能沿y轴负向C.可能沿x轴正向4D..如可图…     

基于DSP的心电信号采集存储系统设计

介绍了一种以TI公司的TMS320LF2407A DSP芯片为核心的实时数据采集存储系统设计方案.该系统通过外接12位AD转换器AD7858来提高DSP采样精度,实时采集病人的心电数据,通过数字滤波处理后可以真实反映病人的心脏健康状况,借助串口电路建立与上位机的通讯.相对于采用PC机和单片机设计的系统,该系统具有功耗小、成本低、实时性强等优点.     

构建新型中等职业教育理念的思考

各国教育理念反映了该国对教育价值的基本取向,对教育理论与实践的发展起着明显的指导作用,为跟上知识经济、城镇化,工业化等发展的步伐,推动社会经济与人的可持续发展,我国必须构建适应时代需求的中职教育理念,以科学指导中职教育的办学定位及其实践.